Card Set Information

2011-02-12 00:34:40

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  1. In what 2 diseases does heparan and dermatan sulfate accumulate?
    • Hurler's
    • Hunters
  2. What enzyme is deficient in Hurlers disease?
    alpha L iduronidase
  3. What enzyme is deficient in Hunter's syndrome?
    Iduronate sulfatase
  4. Which enzyme is deficient in I cell disease?
    GlcNac phosphotransferase
  5. are glycoproteins or proteoglycans branched?
    • glycoproteins branched
    • proteoglycans --unbranched
  6. Enzymes destined for lysosomes are tagged how?
    • Mannose 6 phosphate.
    • Mannose in ER
    • Phosphylation in Golgi Aparatus
  7. O linked glycosidic bonds use what a.a?
    serine, threonine, hydroxylysine
  8. N linked glycosidic bonds use what a.a?
  9. What is the major feature of complex class of oligosaccharides linked to a protein in glycoproteins?
    Sialic Acid
  10. O linked carbs are attached in glycoproteins are attached where?
  11. N linked carbs are attached where?
    What is needed?
    • ER
    • Dolichol phosphate
  12. In glycoproteins the following consensus sequence is attached to a protein: Asn-x-ser/Threonine
    X can be any a.a except?
  13. NANA(sialic acid) is incorporated into a glycoprotein using what high energy molecule
  14. In O glycosidic linked carbs what sugar is used
  15. In N linked glycosidic linked carbs, what sugar is used?
  16. Which is more common, N or O linked?
    N linked
  17. Which one of the glucosaminoglycans is not sulfated and covalently linked to proteins?
    Hyaluronic acid
  18. What the function of Hyaluronic acid?
    • shock absorber
    • lubricant
    • found in synovial fluid, vitreous humor, extracellular matrix
  19. Which one of the GAGs does not have uronic acid?
    Keratan sulfate
  20. Where is Dermatan sulfate found?
    • Skin
    • Blood vessels
    • Heart Valves
  21. Chondroitin sulfates are found where?
    cartilage, tendons
  22. What is the only intracellular GAG
  23. What is the trisaccharide linkage in proteoglycans?
  24. Why are the core proteins of proteoglycans rich in serine and threonine residues??
    So that O linkages to carbs can occur
  25. How are proteoglycan monomers held onto Hyaluronic acid?
    ionic interactions
  26. What is the source of sulfate for proteoglycans?
  27. L gulonate to ascorbate requires what acid that is absent in humans?
    L gulono lactone oxidase
  28. Sulfation and acetylation of proteoglycans occurs when?
    after monosaccharides have been incorporated
  29. What property of GAG explains their reaction?
    they are negatively charged
  30. What is the repeating disaccharide in a GAG?
    Amino sugar-acidic sugar
  31. Proteoglycans bind to what GAG?
    Hyularonic acid
  32. Which gag does not have Uronic acid?
    Keratan sulfate
  33. What takes place of uronic acid in Keratan sulfate?
  34. Are GAGs hetero or homo polysaccharides?
  35. What are the repeating disaccharides units in GAGs?
    D-gluco or galactosamine and D- Gluco or galactoronic acid(Uronic acid)
  36. Which is the GAG that has L sugars and and a variety of other sugars such as NANA?
    Keratan sulfate
  37. What makes up the trihexoside linker protein?
  38. In I cell disease what is not phosphorylated?
    Mannose viA THE deficient enzyme GlcNac phosphotransferase
  39. What is the relation between insulin and potassium?
    Insulin sequesters potassium in cells
  40. How is Hyperkalemia treated?
    • Insulin
    • glucose
  41. What leads to polyphagia in DM?
    • Lack of insulin prevents entry of glucose into satiety center
    • lack of entry of glucose disinhibits hunger center
    • hunger amongst plenty